The eighth mission of the Boeing X-37B spaceplane is officially on as the vehicle is once again in Earth orbit, conducting secret missions.

Autonomous, reusable craft is designed to launch classified, cutting-edge technology for the U.S. Space Force.

The Space Force operates the Global Positioning System satellite network to provide navigation services to ships, airplanes, and land vehicles. Originally conceived as a military service, GPS is now vital to everyday civilian life, whether it's in commercial aviation or finding directions to the nearest gas station.